FRACTURE IN HETEROGENEOUS MATERIALS: EXPERIMENTAL AND THEORETICAL STUDIES
V.S. Kuksenko, Kh.F. Makhmudov
Ioffe Institute, Russian Academy of Sciences, St. Petersburg, 194021, Russia
Keywords: Zone of brittle failure, fracture, prediction, acoustic emission, fracture source, microseismic monitoring
Abstract
The kinetics of fracture in stressed heterogeneous materials is investigated in a differentiated way using the parameter Δ t , the interval between single or multiple (cooperative) microfracture events recorded by acoustic emission (AE) responses. The patterns of fracture nucleation and growth, which is a statistic process, are controlled by the heterogeneity of deforming material. There are two important aspects revealed by the study: 1) structural heterogeneity of materials causes uneven distribution of stress in loaded solids and thus creates local zones of microstress and ensuing microfracture in the overstressed zones; 2) AE measurements and microseismic monitoring are applicable to prediction of fracture by locating its source and thus allows predicting related hazard in mines, tunnels, bridges, nuclear-power plants, and other important engineering objects.
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